The present invention relates to a method and an apparatus for the production of mitered corner joints between two components by vibration welding.
Vibration welding methods for the production of mitered corner joints between frame parts of a rectangular frame, in particular, of a casement frame for windows and doors, are known from the patents EP 1 207 994 B1, EP 1 447 167 A1, EP 1 648 648 A1 and EP 1 656 231 A1. With these vibration welding methods, the frame parts are set into oscillation by the oscillating heads of the vibration welding machines in such a way that the mutually contacting miter areas oscillate in the fixed miter plane (joint plane) oppositely phased under welding pressure in order to incur a frictional welding connection. These oppositely phased oscillations of the mutually contacting miter areas are orbital movements, for example, circular or elliptical movements, which in the extreme case can also be straight-line movements. Because these movements occur in the fixed miter planes, and thus, obliquely to the longitudinal direction of the frame parts, the oscillating heads must also be disposed obliquely to the longitudinal and transverse direction of the frame parts.
From these publications it is further known to produce the four mitered corner joints of a frame simultaneously, in that eight oscillating heads disposed at the corner areas of the frame are driven synchronously.
A similar vibration welding method for producing corner joints of a frame is known from DE 199 38 099 A1, wherein the frame parts are set into linear oscillations perpendicular to the frame plane, in order to rub, and thereby, to weld together the mutually contacting miter areas of the frame parts. With this vibration welding method, as well, the relative movements of the mutually contacting miter areas of the frame parts occur in the fixed miter planes at the four corners of the frame.